A human body is composed of numerous points where the nerve centers are located. Accordingly, the act of rubbing, kneading, etc. of the human body can stimulate the circulation and make the muscles supple. In addition, the act of massage can help relieve tension. In an industrialized nation, people are prone to suffer from fatigue and tension, which are often brought about by the pressure at the working place. It is often difficult for the busy people to find time or an appropriate place to engage in an activity capable of body relaxation and relief of tension. As a result, a variety of exercise devices and massaging devices are made available to the consumers at large. These exercise and massaging devices are not necessarily suitable for use in relaxing the body and relieving tension. The case in point is the back massaging device, which is generally composed of a plurality of rollers, hollow sleeves, center shafts, and two cords. As shown in FIG. 1, the rollers are mounted on the center shafts which are fastened respectively at both ends thereof with two cords. Such a back massaging device of the prior art as described above has inherent shortcomings, which are described hereinafter.
The rollers of the prior art massaging device are made of a wooden material and are provided respectively with an arcuate surface for enhancing the massaging effect. In the first place, the wooden rollers are rather expensive. The additional work done for providing each of the wooden rollers with an arcuate surface will no doubt result in an increase in the cost of making the massaging device. In addition, the rollers and the center shafts are located by means of the sleeves which incur additional expenses.
The production efficiency of the prior art back massaging device is poor in view of the fact that the assembly of rollers, center shafts, sleeves and cords is labor-intensive and can not be done easily and rapidly. In other words, a mass production of the prior art massaging device can not be attained in a short period of time.
The back massaging device of the prior art is not provided with an excellent massaging effect in view of the fact that the arcuate surfaces of the rollers of the massaging device are incapable of stimulating the points where the nerve centers of the back are located.
The replacement of a damaged or cracked roller of the prior art massaging device can not be done easily. To replace just one roller, it is necessary to dismantle the entire massaging device. Since the damaged or cracked roller can inflict a skin injury on the back of a user of the massaging device, it is imperative that the massaging device having damaged or cracked rollers should not be used.